Mozilla Firefox is a fast, full-featured Web browser. Firefox includes pop-up blocking, tab-browsing, integrated Google search, simplified privacy controls, a streamlined browser window that shows you more of the page than any other browser and a number of additional features that work with you to help you get the most out of your time online.

What is new in this release:

Improved warning pages for certificate errors and untrusted connections
Enable H.264 if system decoder is available
Enable WebM/VP9 video support on systems that don't support MP4/H.264
In the animation-inspector timeline, lightning bolt icon next to animations running on the compositor thread
Support the brotli compression format via HTTPS content-encoding
Screenshot commands allow user choice of pixel ratio in Developer Tools